locked out of phone after removing SIM

Hi,

I have just removed SIM from my old phone and got a new SIM [different format, now nano] for use with my new handset.

Since removing from my old HTC One I now cannot access the phone and doesn’t seem to accept the PIN I thought was correct.

I haven’t got a working SIM now that will fit in the HTC One.

How can I unlock it please?

Thanks - Oliver :-[

Hi,

so you can’t insert the old SIM anymore?

Filip